GPT-5.5 Pro vs DeepSeek V4 Flash

GPT-5.5 Pro from OpenAI and DeepSeek V4 Flash from DeepSeek are shown side by side so you can compare pricing, model IDs, context and output limits, modalities, tool use, release details, and benchmark results where data is available.

Overall Recommendation

GPT-5.5 Pro is the stronger quality default for difficult professional and multimodal work. DeepSeek V4 Flash is the clear throughput option when ultra-low $0.15/$0.30 pricing outweighs peak capability.

Comparison Highlights

Based On Current Page Data

GPT-5.5 ProOpenAI

DeepSeek V4 FlashDeepSeek

How To Read It

Best For

Highest-difficulty professional reasoningdeliverables

High-throughputcost-sensitive long-context workloads

How To Read ItUse-case synthesis from model capabilities and positioning.

Workload Fit

Pro reasoningCodingResearch

ThroughputLow costLong context

How To Read ItThe workloads each model is most directly shaped for.

Input

$30/M

$0.4286/MEdge

How To Read ItLower is better when prompts or retrieval payloads are large.

Output

$180/M

$1.2857/MEdge

How To Read ItLower is better for reasoning-heavy or long-generation traffic.

Context length

1.1M

How To Read ItHigher is better for repositories, retrieval packs, and transcripts.

Input modalities

Image, PDF, TextEdge

Text

How To Read ItBroader input support reduces the need for separate vision or video models.

Model Selection Guide

GPT-5.5 ProOpenAI

Choose GPT-5.5 Pro When

TokenHub positions it as the high-compute GPT-5.5 tier for the hardest professional tasks
$30 input and $180 output per million tokens, prioritizing answer quality over cost
A 1.05M context window, 128K maximum output, and text, image, and PDF input

DeepSeek V4 FlashDeepSeek

Choose DeepSeek V4 Flash When

The lowest listed price: $0.15 input and $0.30 output per million tokens
A 40.3 Intelligence Index and 38.7 Coding Index in TokenHub’s max-effort profile
A 1M context window and 384K maximum output for high-volume text workloads

Basic Information

GPT-5.5 ProOpenAI

DeepSeek V4 FlashDeepSeek

Name

GPT-5.5 Pro

Model id

gpt-5.5-pro

Intro

GPT-5.5 Pro is the higher-compute variant of OpenAI’s GPT-5.5 generation, intended for the hardest professional tasks where answer quality matters more than speed. OpenAI materials describe the Pro tier as thinking harder for greater precision across coding, research, data analysis, and document-heavy work. It should be positioned for difficult reasoning and professional-grade deliverables rather than routine chat.

Author

OpenAI

Released date

2026-04-23

Context length

1.1M

Max output tokens

128K

Name

DeepSeek V4 Flash

Model id

deepseek-v4-flash

Intro

DeepSeek V4 Flash keeps the V4 family’s 1M-token context window but uses a lighter MoE configuration, commonly described as 284B total parameters with 13B activated parameters. The emphasis is throughput: fast inference, lower cost per call, and production workloads that still need long-context handling. It is the better fit when the task volume is high and the workload benefits from V4-style long-context architecture without always requiring the deepest reasoning tier.

Author

DeepSeek

Released date

2026-04-24

Context length

Max output tokens

384K

Name

GPT-5.5 Pro

Name

DeepSeek V4 Flash

Model id

gpt-5.5-pro

Model id

deepseek-v4-flash

Intro

Author

OpenAI

Author

DeepSeek

Released date

2026-04-23

Released date

2026-04-24

Context length

1.1M

Context length

Max output tokens

128K

Max output tokens

384K

Pricing

GPT-5.5 ProOpenAI

DeepSeek V4 FlashDeepSeek

Input

$30/M

Output

$180/M

Cached input

n/a

Input

$0.4286/M

Output

$1.2857/M

Cached input

$0.0143/M

Input

$30/M

Input

$0.4286/M

Output

$180/M

Output

$1.2857/M

Cached input

n/a

Cached input

$0.0143/M

Capabilities

GPT-5.5 ProOpenAI

DeepSeek V4 FlashDeepSeek

Reasoning

Knowledge

2025-12-01

Attachment

Input modalities

Image, PDF, Text

Output modalities

Text

Temperature

Tool use

Reasoning

Knowledge

2025-05-01

Attachment

Input modalities

Text

Output modalities

Text

Temperature

Tool use

Reasoning

Knowledge

2025-12-01

Knowledge

2025-05-01

Attachment

Input modalities

Image, PDF, Text

Input modalities

Text

Output modalities

Text

Output modalities

Text

Temperature

Tool use

Benchmark

GPT-5.5 ProOpenAINo benchmark data

DeepSeek V4 FlashDeepSeek

Intelligence

n/a

Coding

n/a

Intelligence

wins40.3

Coding

wins38.7

Knowledge & Reasoning

GPQA

n/a

HLE

n/a

GPQA

wins89.4%

HLE

wins32.1%

Coding

SciCode

n/a

Terminal-Bench Hard

n/a

SciCode

wins44.9%

Terminal-Bench Hard

wins35.6%

Instruction Following & Agent Tasks

IFBench

n/a

AA-LCR

n/a

Tau2

n/a

IFBench

wins79.2%

AA-LCR

wins63%

Tau2

wins95.0%

FAQ

Which model is better, GPT-5.5 Pro or DeepSeek V4 Flash?

GPT-5.5 Pro and DeepSeek V4 Flash should be compared by workload. This page places price, context, output limits, capabilities, and benchmark data side by side. It is also relevant to: deepseek vs chatgpt, chatgpt vs deepseek, deepseek vs chatgpt comparison, deepseek ai vs chatgpt, deepseek vs openai, openai vs deepseek.

Is DeepSeek V4 Flash cheaper than GPT-5.5 Pro?

Use the pricing rows above to compare input, output, and cached input prices for GPT-5.5 Pro and DeepSeek V4 Flash.

Which model supports a longer context length?

GPT-5.5 Pro lists 1.1M context length, while DeepSeek V4 Flash lists 1M.

Can I access both models through TokenHub?

If both models are available in the TokenHub catalog, you can route requests to GPT-5.5 Pro and DeepSeek V4 Flash through the TokenHub API.